Gil rolls a number cube 78 times how many times can he expect to roll an odd number greater than 1

Sagot :

Odd numbers greater than 1 on a number cube are 3 and 5. The probability of rolling one of those two numbers is 2 out of 6 (2/6), which can be simplified to 1/3 by dividing both the numerator and denominator by 2.

If he rolls the cube 78 times and every time there is a 1/3 chance of rolling 3 or 5, then to calculate how many times he can expect to roll those numbers, we must multiply 78/1 by 1/3.

78/1 x 1/3 = 78/3

78/3 = 26

He can expect to roll an odd number greater than one 26 times.
im assuming its just a regular number cube with 6 numbers 
there are only 2 odd numbers above 1 ( 3 and 5) 

so the ratio is 2/6 

you want to know how manny times (x) will you roll those numbers out of 78 roll 
the ratio is x/78 

multiply 

(2/6) = (x/78) 

cross multply to give you 6x= 156 and divide by 6 

to give you x = 26